LMK Lenses

LMK NED (AR/VR/MR) LENSES

LMK 6
Features
Imaging with the LMK using specially adapted lenses offers an effective and efficient alternative for metrological characterization of near-eye display (NED) systems.
When you use a NED system, you only perceive the entire image field if your eyes are within the so-called eye-box of the NED system. For each eye, the eye-box corresponds to a 3-dimensional space around the respective exit pupil of the optical system.
Often the diameter of the NED exit pupil is larger than in conventional optical instruments (e.g., microscopes) and the distance to the last optical surface (eye-relief) is relatively small.
 

For a correct and perceptually accurate photometric or colorimetric measurement, the entrance pupil of the measuring system must be located in the exit pupil of the NED system, analogous to the human eye. On the other hand, it must be ensured that the entrance pupil of the measuring system is smaller than the exit pupil of the NED system in order to achieve full coverage of the measuring system's aperture. This is how valid measurement data can be guaranteed.
If the LMK is to cover the complete NED field of view, the LMK entrance pupil must be placed in the NED exit pupil inside the eye box. This requires an optical system whose aperture diaphragm (or entrance pupil) is located in front of the optical surfaces.

Besides the existing conoscopic lens that offers a virtual entrance pupil (appr. 2mm diameter) in front of the lens and a measuring field of 120°, TechnoTeam also offers a special front-stop lens.
This front-stop lens works with a real intermediate image plane and can be equipped with several focal lengths of 8mm; 12mm and 16mm. They offer a measuring field of 30°- 60°. The diameter of the entrance pupil can be changed from 2 - 7mm.

Lens

LMK 6-12

LMK 6-30

TT35 NED

x

x

TT50 NED

x

x

TechnoTeam offers two different front-stop lenses for the LMK 6 model for the characterization and metrology of near-eye display (NED) systems. The lenses can be further adapted to customer specifications.

NED lenses for the LMK 6-12

Lens type TT35 NED TT50 NED
Focus type manual focus manual focus
Focal length 35 mm 50 mm
Measuring distance > 200 mm > 500 mm
Measuring field angle ≈ 26° × 19° ≈ 15° × 11°
Length ≈ 36 mm ≈ 84 mm

NED lenses for the LMK 6-30

Lens type TT35 NED TT50 NED
Focus type manual focus manual focus
Focal length 35 mm 50 mm
Measuring distance > 200 mm > 500 mm
Measuring field angle ≈ 39° × 29° ≈ 24° × 18°
Length ≈ 36 mm ≈ 84 mm
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